Modelling Induction Generators in PTW

Although PTW does not have a specific induction generator model (it only has a synchronous generator model), induction generators can be easily modelled. A synchronous generator has its own excitation system, whereas an induction generator takes its excitation by absorbing reactive power from the rest of the network.

An induction generator should be modelled as a PQ generator when running a load-flow. The values should be set to absorb reactive power and produce active power. A network must always have a swing-bus generator to run a study; this is not a problem because an induction generator will always be connected to an external source of reactive power.

As far as the Comprehensive Fault Study is concerned, there is no difference between an induction generator and a synchronous generator, so the standard model can be used. The IECFault study does, on the other hand, consider the excitation of machines. Unfortunately, the IEC60909 standard does not address the use of induction generators, so an induction generator cannot "officially" be modelled in IECFault.

The I*SIM module has an induction generator model as one of the standard generator models. Although its exact behaviour will depend on the network and the scenarios modelled, an induction generator will generally continue to operate until there is insufficient stored energy to continue.